What challenge options are there for the London Duathlon?

There are 4 options to take part in the event: 

• Full Duathlon – Individual entry: 10k run / 44k bike / 5k run  
• Half Duathlon – Individual entry: 5k run / 22k bike / 5k run 
• Ultra Duathlon – Individual entry: 20k run/ 77k bike/ 10k run 
• Relay Duathlon – Team Entry: 10k run / 44k bike / 5k run (Split between each team member). Relay teams can have either 2 or 3 people in each team.